Swammerdamella ramulosa, Xiao & Hong & Li & Yang, 2025

Xiao, Yishen, Hong, Dawei, Li, Zhu & Yang, Ding, 2025, First report of the genus Swammerdamella Enderlein, 1912 (Diptera: Scatopsidae) in China, with descriptions of nine new species, Zootaxa 5723 (1), pp. 49-70 : 62-64

11. Swammerdamella ramulosa sp. nov. āäDzĸxü

( Figs. 7A–7E )

Diagnosis. M fork complete and shorter than stem. Sternite 6 of male unmodified, with a row of setae on posterior margin. Male tergite 7 devoid of median process and with 3 concavities. Aedeagus long, sclerotised and thin.

Description. Male ( Fig. 7A ). Body length about 1.3 mm, wing length 1.1 mm.

Head. Dull brown, higher than long; antennae 10-segmented; flagellum 8-segmented, each flagellomere with a whorl of microtrichia; last flagellomere distinctly elongate, twice as long as preceding one, with about 3 whorls of microtrichia; eyes holoptic; palpus one-segmented, light brown, and elongate.

Thorax. Dull brown, stout and matte; scutum densely pilose. Anterior spiracular sclerite triangular. Halters concolorous with scutum, stem with a row of setae. Legs short, mostly concolorous with body except for the yellowish-brown tarsi.

Wing ( Fig. 7B ). Membrane nearly hyaline; anterior veins sclerotized and light brown, R 1 and R 4+5 joining costa close to each other; M fork complete but hardly visible, shorter than stem of M; CuA sigmoid, smoothly bent; a sparse row of macrotrichiae on whole posterior margin of wing.

Abdomen. Strong, stout and dull brown; segments 1–6 visible; sternite 6 ( Fig. 7C ) wide, sparsely setose, posterior margin unmodified; tergite 6 missing during the dissection, but obviously with a relatively unmodified posterior margin ( Fig. 7A ). Segment 7 ( Fig. 7E ) retracted into segment 6; tergite 7 without setae and ventral process, lateral arms wide and rounded apically; sternite 7 rounded, inner margin setose, with 2 symmetric angles and a shallow median concavity.

Male terminalia ( Fig. 7D ). Longer than wide; aedeagus thin, long, and darker than other parts, rounded apically and basally with 2 sharp angles. Two lobes dorsally pointed, sclerotized, and bifurcated apically, forming a pair of twig-like projections.

Female. Unknown.

Type Material. HOLOTYPE: ♂, China, Guangxi Province, Leye [ 乐业], Yachang Nature Reserve [ ǎẗnẍ 保ae区] [ 24°50’ N, 106°12’ E, 612m], collected by sweep net, 2024. VIII. 8, Wei Zeng ( CAU).

Distribution. China ( Guangxi Province).

Etymology. This specific name is derived from the Latin noun “ramulus”, which means “twig” or “little branch”, referring to the twig-like projections of male terminalia.

Remarks. S. ramulosa is another new species from the Oriental Region and can be distinguished from other Swammerdamella species by the characteristics of tergite 7. The shape of tergite 7 is somewhat twisted and concave, with a large concavity in the middle and other 2 smaller ones on both sides, and without ventral process.

Figures

FIGURE 7A–7B. 7A. Swammerdamella ramulosa sp. nov., male adult. 7B. Wing. 7C. Male sternite 6. 7D. Male terminalia. 7E. Male segment 7. Scale bar 1.0 mm (7A–7B), 0.1 mm (7C–1E).